Bisphosphonate-mediated gene vector delivery from the metal surfaces of stents

Proc Natl Acad Sci U S A. 2006 Jan 3;103(1):159-64. doi: 10.1073/pnas.0502945102. Epub 2005 Dec 21.

Abstract

The clinical use of metallic expandable intravascular stents has resulted in improved therapeutic outcomes for coronary artery disease. However, arterial reobstruction after stenting, in-stent restenosis, remains an important problem. Gene therapy to treat in-stent restenosis by using gene vector delivery from the metallic stent surfaces has never been demonstrated. The present studies investigated the hypothesis that metal-bisphosphonate binding can enable site-specific gene vector delivery from metal surfaces. Polyallylamine bisphosphonate (PAA-BP) was synthesized by using Michael addition methodology. Exposure to aqueous solutions of PAA-BP resulted in the formation of a monomolecular bisphosphonate layer on metal alloy surfaces (steel, nitinol, and cobalt-chromium), as demonstrated by x-ray photoelectron spectroscopy. Surface-bound PAA-BP enabled adenoviral (Ad) tethering due to covalent thiol-binding of either anti-Ad antibody or a recombinant Ad-receptor protein, D1. In arterial smooth muscle cell cultures, alloy samples configured with surface-tethered Ad were demonstrated to achieve site-specific transduction with a reporter gene, (GFP). Rat carotid stent angioplasties using metal stents exposed to aqueous PAA-BP and derivatized with anti-knob antibody or D1 resulted in extensive localized Ad-GFP expression in the arterial wall. In a separate study with a model therapeutic vector, Ad-inducible nitric oxide synthase (iNOS) attached to the bisphosphonate-treated metal stent surface via D1, significant inhibition of restenosis was demonstrated (neointimal/media ratio 1.68 +/- 0.27 and 3.4 +/- 0.35; Ad-iNOS vs. control, P < 0.01). It is concluded that effective gene vector delivery from metallic stent surfaces can be achieved by using this approach.

Publication types

  • Comparative Study
  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adenoviridae / metabolism
  • Angioplasty / methods*
  • Animals
  • Cells, Cultured
  • Coronary Artery Disease / complications
  • Coronary Artery Disease / surgery*
  • Diphosphonates / metabolism*
  • Genes, Reporter / genetics
  • Genetic Therapy / methods*
  • Genetic Vectors / metabolism
  • Genetic Vectors / therapeutic use*
  • Graft Occlusion, Vascular / etiology
  • Graft Occlusion, Vascular / therapy*
  • Green Fluorescent Proteins / metabolism
  • Male
  • Nitric Oxide Synthase Type II / metabolism
  • Polyamines / metabolism
  • Rats
  • Rats, Sprague-Dawley
  • Spectrum Analysis
  • Stents*
  • Transduction, Genetic / methods

Substances

  • Diphosphonates
  • Polyamines
  • Green Fluorescent Proteins
  • polyallylamine
  • Nitric Oxide Synthase Type II
  • Nos2 protein, rat